Error analysis in maximum subarray sum 2

#1

in line 35 where current sum=cumsum[j]-cumsum[i-1]
and we have initialise i as 0 then when in first itteration
currentsum=cumsum[0]-cumsum[-1]
then what does cumsum[-1] means

#2

@Bhavit_Singla hey bhavit you are right this implementation is little bit wrong I will send you the right implementation.